I am going to build an enclosure for 3 8w6 and am going to need every bit of space I can to make it just big enough. One of my thoughts is to use 1/2 inch instead of 5/8 or 3/4. The tops and bottom of the enclosure will be Fiberglass but the front, back and sides will be MDF. The front height should be no more than 6 1/2 inches with a span of 30 inches. The rear will be no more than 4 inches with the longest span being 16 inches. I figured I could get away with using the 1/2 inch by adding a couple of braces to the longest span. What do you all think?